1. Field of the Invention
The present invention relates to a metal air battery, generally called a coin cell, having a cathode in the container. The shape of metal-air batteries in general is disk shaped with diameter of less than 25.4 millimeters and a height under 12.7 millimeters. As shown in FIG. 1, a metal-air battery should have at least one port on the cathode container bottom for exchanging gas outside the battery so that oxygen in the air acts as a cathode.
2. Description of the Related Art
As shown in FIG. 3, cathode container (1) has an open end and a closed end. The bottom side (2) of the closed end has a port (3). Inside the container (1) is hydrophobic film (4) made of PTFE (Teflon) film and a cathode (5). Electrolyte (8) is housed in an anode container (7) having the open end thereof extending into the cathode container and having a gasket (6) compressed between the anode and the cathode containers.
Insufficient airflow in a metal-air battery can result in poor performance and can shorten the battery life. When metal-air batteries are stored, they are generally sealed with adhesive tape to prevent air diffusion during storage. When removed from storage the metal-air battery needs to be activated by removing adhesive tape and allowing air flow into the battery. The air flow necessary to activate the battery and maintain useful performance and lifetime, however, is often more than what can be received through the port.
The present invention relates to metal-air batteries that address the aforementioned concerns. The purpose of the invention is to improve current drain, shorten activation time after peeling off the seal sticker and maximize battery lifetime by creating a system of gas diffusion passages which provide air chambers between the cathode container and the cathode.